Install the callbacks via the state machine.
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
v1…v2: remove debug pr_err()
include/linux/cpuhotplug.h | 1 +
include/linux/slab.h | 8 ++++
kernel/cpu.c | 7 ++-
mm/slab.c | 116 ++++++++++++++++++++-------------------------
4 files changed, 67 insertions(+), 65 deletions(-)
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 4c79f40fcebc..c2cf14953abc 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -22,6 +22,7 @@ enum cpuhp_state {
CPUHP_X2APIC_PREPARE,
CPUHP_SMPCFD_PREPARE,
CPUHP_RELAY_PREPARE,
+ CPUHP_SLAB_PREPARE,
CPUHP_RCUTREE_PREP,
CPUHP_NOTIFY_PREPARE,
CPUHP_TIMERS_DEAD,
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 4293808d8cfb..084b12bad198 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -650,4 +650,12 @@ static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
unsigned int kmem_cache_size(struct kmem_cache *s);
void __init kmem_cache_init_late(void);
+#if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
+int slab_prepare_cpu(unsigned int cpu);
+int slab_dead_cpu(unsigned int cpu);
+#else
+#define slab_prepare_cpu NULL
+#define slab_dead_cpu NULL
+#endif
+
#endif /* _LINUX_SLAB_H */
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 2a11381d5997..82bf61c67316 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -24,6 +24,7 @@
#include <linux/irq.h>
#include <linux/smpboot.h>
#include <linux/relay.h>
+#include <linux/slab.h>
#include <trace/events/power.h>
#define CREATE_TRACE_POINTS
@@ -1273,6 +1274,11 @@ static struct cpuhp_step cpuhp_bp_states[] = {
.startup = relay_prepare_cpu,
.teardown = NULL,
},
+ [CPUHP_SLAB_PREPARE] = {
+ .name = "SLAB prepare",
+ .startup = slab_prepare_cpu,
+ .teardown = slab_dead_cpu,
+ },
[CPUHP_RCUTREE_PREP] = {
.name = "RCU-tree prepare",
.startup = rcutree_prepare_cpu,
@@ -1376,7 +1382,6 @@ static struct cpuhp_step cpuhp_ap_states[] = {
.startup = rcutree_online_cpu,
.teardown = rcutree_offline_cpu,
},
-
/*
* Online/down_prepare notifiers. Will be removed once the notifiers
* are converted to states.
diff --git a/mm/slab.c b/mm/slab.c
index 0eb6691ae6fc..1cecd9fe23e3 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -887,6 +887,7 @@ static int init_cache_node(struct kmem_cache *cachep, int node, gfp_t gfp)
return 0;
}
+#if (defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)) || defined(CONFIG_SMP)
/*
* Allocates and initializes node for a node on each slab cache, used for
* either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node
@@ -909,6 +910,7 @@ static int init_cache_node_node(int node)
return 0;
}
+#endif
static int setup_kmem_cache_node(struct kmem_cache *cachep,
int node, gfp_t gfp, bool force_change)
@@ -976,6 +978,8 @@ static int setup_kmem_cache_node(struct kmem_cache *cachep,
return ret;
}
+#ifdef CONFIG_SMP
+
static void cpuup_canceled(long cpu)
{
struct kmem_cache *cachep;
@@ -1076,65 +1080,54 @@ static int cpuup_prepare(long cpu)
return -ENOMEM;
}
-static int cpuup_callback(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
+int slab_prepare_cpu(unsigned int cpu)
{
- long cpu = (long)hcpu;
- int err = 0;
+ int err;
- switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- mutex_lock(&slab_mutex);
- err = cpuup_prepare(cpu);
- mutex_unlock(&slab_mutex);
- break;
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
- start_cpu_timer(cpu);
- break;
-#ifdef CONFIG_HOTPLUG_CPU
- case CPU_DOWN_PREPARE:
- case CPU_DOWN_PREPARE_FROZEN:
- /*
- * Shutdown cache reaper. Note that the slab_mutex is
- * held so that if cache_reap() is invoked it cannot do
- * anything expensive but will only modify reap_work
- * and reschedule the timer.
- */
- cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu));
- /* Now the cache_reaper is guaranteed to be not running. */
- per_cpu(slab_reap_work, cpu).work.func = NULL;
- break;
- case CPU_DOWN_FAILED:
- case CPU_DOWN_FAILED_FROZEN:
- start_cpu_timer(cpu);
- break;
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- /*
- * Even if all the cpus of a node are down, we don't free the
- * kmem_cache_node of any cache. This to avoid a race between
- * cpu_down, and a kmalloc allocation from another cpu for
- * memory from the node of the cpu going down. The node
- * structure is usually allocated from kmem_cache_create() and
- * gets destroyed at kmem_cache_destroy().
- */
- /* fall through */
-#endif
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
- mutex_lock(&slab_mutex);
- cpuup_canceled(cpu);
- mutex_unlock(&slab_mutex);
- break;
- }
- return notifier_from_errno(err);
+ mutex_lock(&slab_mutex);
+ err = cpuup_prepare(cpu);
+ mutex_unlock(&slab_mutex);
+ return err;
}
-static struct notifier_block cpucache_notifier = {
- &cpuup_callback, NULL, 0
-};
+/*
+ * This is called for a failed online attempt and for a successful
+ * offline.
+ *
+ * Even if all the cpus of a node are down, we don't free the
+ * kmem_list3 of any cache. This to avoid a race between cpu_down, and
+ * a kmalloc allocation from another cpu for memory from the node of
+ * the cpu going down. The list3 structure is usually allocated from
+ * kmem_cache_create() and gets destroyed at kmem_cache_destroy().
+ */
+int slab_dead_cpu(unsigned int cpu)
+{
+ mutex_lock(&slab_mutex);
+ cpuup_canceled(cpu);
+ mutex_unlock(&slab_mutex);
+ return 0;
+}
+#endif
+
+static int slab_online_cpu(unsigned int cpu)
+{
+ start_cpu_timer(cpu);
+ return 0;
+}
+
+static int slab_offline_cpu(unsigned int cpu)
+{
+ /*
+ * Shutdown cache reaper. Note that the slab_mutex is held so
+ * that if cache_reap() is invoked it cannot do anything
+ * expensive but will only modify reap_work and reschedule the
+ * timer.
+ */
+ cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu));
+ /* Now the cache_reaper is guaranteed to be not running. */
+ per_cpu(slab_reap_work, cpu).work.func = NULL;
+ return 0;
+}
#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
/*
@@ -1337,12 +1330,6 @@ void __init kmem_cache_init_late(void)
/* Done! */
slab_state = FULL;
- /*
- * Register a cpu startup notifier callback that initializes
- * cpu_cache_get for all new cpus
- */
- register_cpu_notifier(&cpucache_notifier);
-
#ifdef CONFIG_NUMA
/*
* Register a memory hotplug callback that initializes and frees
@@ -1359,13 +1346,14 @@ void __init kmem_cache_init_late(void)
static int __init cpucache_init(void)
{
- int cpu;
+ int ret;
/*
* Register the timers that return unneeded pages to the page allocator
*/
- for_each_online_cpu(cpu)
- start_cpu_timer(cpu);
+ ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "SLAB online",
+ slab_online_cpu, slab_offline_cpu);
+ WARN_ON(ret < 0);
/* Done! */
slab_state = FULL;
--
2.9.3
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